Manually-actuated metering pump

ABSTRACT

The invention relates to a manually-actuated metering pump of simple design, which is intended for a rigid container. The inventive metering pump is of the dual valve type, comprising a lower inlet valve and an upper ejection valve which are disposed at the input and output respectively of a metering chamber which is slidably mounted on the lower valve. Moreover, said lower valve is fixed to a hollow tube which communicates with the inside of the container. The invention can be used for dispensing fluid products.

The present invention relates to a metering pump for dispensing fluid,liquid or pasty products, and more particularly to a manually actuatedmetering pump for a rigid bottle having a flexible pouch or a piston anddip tube, containing a fluid, liquid or pasty product intended to bedelivered in constant individual doses, and to a dispensing deviceequipped with such a pump.

The operating principle of metering pumps for dispensing fluid, liquidor pasty products is well known. These pumps are mounted on a bottlecontaining the product to be dispensed and are formed from a meteringchamber of defined volume, a piston capable of moving in the chamberunder the action of a pusher, and at least two valves. The lower valve,or intake valve, located at the inlet of the chamber and controlling thecommunication with the inside of the bottle, is closed when the pusheris pushed right in, while the lower valve, at the outlet of the chamber,is open, allowing the product expelled from the chamber by thedisplacement of the piston to pass, and then, when the pusher isreleased, the piston rises back up in the chamber under the action of aspring, the upper valve closes, while the lower valve opens, making itpossible to fill the chamber for the purpose of dispensing a new dose ofproduct.

This mode of operation means that air can be introduced into the bottleto make up for the volume released by the product expelled from thebottle and can allow the metering chamber to be uniformly filled at eachactuation of the pusher.

To package and dispense products that have to be kept away from air,especially in the field of pharmaceutical and cosmetic products, devicesare known that generally comprise a container with a rigid shell inwhich a piston moves, said piston pushing the product toward the inletorifice in the metering chamber and isolating it from the air thatpenetrates above the piston. Also known are devices with a rigidcontainer in which a flexible pouch is placed, said pouch retractingprogressively as the product is extracted therefrom. The productremaining in the pouch is kept away from air, whereas the expulsion ofthe product out of the pouch can be achieved by means of an airlesspump, or under the pressure of a propellant gas that acts on the wall ofthe pouch, inside the bottle.

In the case of expulsion of the product from the pouch by means of anairless pump, a vent is provided, generally in the bottom or in the neckof the bottle, in order to allow external air to enter into the spacelying between the bottle and the pouch at each actuation of the pump,and thus to allow the pouch to retract while maintaining sufficientpressure on its walls. One illustrative example according to thistechnique is disclosed in patent FR 2 723 356 relating to a device thatincludes a flexible plastic pouch, such as one made of polyethylene orpolypropylene, in a rigid container whose neck includes an air inlet.

The pumps must provide good sealing and be able to operate both in avertical position and in an inclined position. Patent FR 2 669 379discloses a metering pump that ensures good sealing even in thesituation when there is a change of position, of the type with an axialpiston, carrying a sliding floating piston, having three valves. PatentFR 2 726 810 discloses an example of an airless pump in which the lowervalve is flexible and frustoconical, while the upper valve is carried bya disk placed at the base of the hollow stem of the pusher. However,pumps of this type have the drawback of comprising a relatively largenumber of components, which weakens them and increases theirmanufacturing cost.

Patent EP 0 538 162 discloses a closure device for a bottle, one variantof which includes a hollow pusher forming a metering chamber, between anoutput valve and an intake valve; when the pusher is actuated, the baseof the part forming the lower valve is pushed back and deforms,therefore making it easier for the truncated cone surrounding the axialcylindrical part to open, which runs the risk of causing fluid to returninto the bottle. Patent application WO 95/25945 relates to a pump thatincludes a deformable lower valve and an expulsion valve, the orifice ofwhich is similar, but the dimensions and the functions of which aredifferent. Other examples of dispensing bottles with a hollow pusher aredisclosed in patents EP 888 823 and EP 733 559. In all these dispensingbottles, the valves have different shapes, dimensions and functions.

The subject of the present invention is an airless metering pump fordispensing fluid, liquid or pasty products, which has a small number ofcomponents.

The subject of the present invention is also an airless metering pumpfor uniform dispensing of constant individual doses of fluid, liquid orpasty products.

The subject of the invention is also a device for packaging anddispensing fluid, liquid or pasty products, of the type consisting of arigid bottle with a flexible pouch, comprising a metering pump asdescribed above, which ensures satisfactory operation irrespective ofthe position of the rigid bottle.

The subject of the invention is also a device for packaging anddispensing fluid or liquid products of the type consisting of a rigidbottle with a vent, comprising a metering pump as described above,sealably mounted on a bottle provided with a vent.

According to the present invention, the manually actuated metering pump,for a rigid bottle, is of the double-valve type, comprising an intakelower valve and an expulsion upper valve at the inlet and at the outlet,respectively, of a metering chamber that is mounted so as to slide onthe lower valve, and is noteworthy in that the lower valve and the uppervalve are identical.

According to a preferred embodiment of the invention, the lower valve isfixed to a hollow tube that communicates with the pouch, while the uppervalve is mounted on the end of the outlet nozzle of the pump. Thisembodiment has the advantage of constituting an outermost closure thatcompletely eliminates the product dead volume at the outlet of thepusher, thereby making it easier to preserve said product and avoid anyunsightly accumulation of product at the outlet of the pusher whichcould, by drying out, block the output nozzle.

The lower valve, on which the pump chamber slides, acts as a piston,thereby simplifying the manufacture of the pump.

According to another preferred feature of the invention, the two valves,namely the lower and upper valves, are identical and interchangeablewhen mounting the device, which considerably simplifies its manufactureand greatly reduces its cost.

According to one simple and inexpensive embodiment, the valves areformed by a cylindrical cover made of an elastic material pierced at itscenter and fixed to a cylindrical part forming a support and comprisingan annular orifice surrounding, at its center, an element facing thehole in the cover and masking the latter. At rest, the front wall of thecover covers the annular orifice and bears on the central element. Thus,the valve is closed. An external overpressure presses the wall of thecover against its support and therefore keeps the valve closed. Incontrast, an internal overpressure causes the elastic blade of the frontwall of the cover to rise, exposing the annular orifice and causing thevalve to open.

According to one preferred embodiment of the invention, the valves areof cylindro-conical shape, comprising a dome pierced at its center, thewall of which, in the closure position, covers the annular orificeoutlet nozzle in a plane perpendicular to the outgoing flow of fluid.More particularly, the wall of the valve, in its domed portion, coversthe annular orifice, substantially perpendicularly to its axis, andbears on the cylindrical central element lying along the axis of theorifice. This arrangement makes it possible to combine the valve with anorifice of relatively large cross section both as regards the intakelower valve and the expulsion upper valve.

The valves may be made of any material exhibiting the desiredflexibility and elasticity properties and compatible with the productscontained in the bottle. As an example, it is possible to use valvesmade of natural or synthetic rubber or made of thermoplastic elastomers,such as thermoplastic polyesters, polyurethanes or SBS, or evensilicones.

According to one advantageous embodiment of the present invention, thevalves are made of a material having a Shore A hardness of between 40and 80, preferably between 50 and 60.

According to the invention, it may be advantageous to mount the pumpsealably on the rigid bottle via a ring or a cap. According to avariant, the pump is mounted directly on the bottle, for example bysnap-fitting.

According to one advantageous embodiment, the pusher includes means forlimiting its travel and for adapting the dose to a predefined volume.These means may be produced by providing, for example, one or more stopsplaced on the moving portion of the pusher and co-operating withcomplementary means on the fixed portion, or by varying the length ofthe cylindrical portion of the pusher, or else by inserting a sleevethat limits the stroke of the pusher on the support. It is thus possibleto have devices for dispensing fluid products that are designed toprovide different doses of product, by only modifying a singleconstituent element, or by inserting a simple complementary element.Such a system is particularly inexpensive.

An air inlet circuit is provided so that the external air can enter thebottle and compensate for the volume of product expelled by the pump.

In the case of a device of the type consisting of a rigid bottle with aflexible pouch, the external air must reach the space separating theflexible pouch from the inner wall of the rigid bottle in order tomaintain sufficient pressure therein so that the pouch can retract ateach expulsion of product. This air circuit is preferably located levelwith the pusher of the pump, and it comprises means for ensuring that itis closed off when the pusher is raised, in the rest position.

In the case of a simple rigid bottle, with or without a scraper piston,the air circuit may be formed by a vent, preferably in the bottom of thebottle.

Thus, according to one advantageous embodiment, in the bottom of therigid bottle there is a vent provided with a valve, in order to avoidany leakage of the product contained in the bottle, and with a filterfor preventing the ingress of contaminants, such as bacteria, whichcould degrade the product to be dispensed.

In the variant that includes a vent in the bottom of the bottle, it ispreferable to provide a dip tube that extends the pump into the bottle,the end of the dip tube possibly being located near the bottom of thebottle.

To ensure proper sealing of the assembly, formed by the bottle, the pumpand optionally the flexible pouch, including in situations in which thisassembly would be in a region of pressure low enough to be able to causethe two valves to open, in the case of identical valves, and of causingthe product contained in the metering chamber and in the bottle to leak,a cap or cover may be removably mounted on the dispensing head.

Means may be provided for ensuring that a seal is formed by the fittingarrangement between the cover and the head, for example the cover may beput into place by snap-fitting it thanks to shape complementaritybetween the internal edge of the cover and the base of the pusher nosereceiving it, this fitting arrangement being supplemented with an O-ringseal or with sealing beads.

Such an accessory supplementing the pump and its pusher ensures thatthere is excellent sealing under all storage conditions, even when theexternal pressure drops, and allows the product contained in the bottleto be preserved.

The pump according to the present invention has the advantage ofcomprising only a limited number of components, thereby reducing themanufacturing costs. Thus, the pump of the invention comprises only fiveor six components, depending on the configuration adopted. In addition,the lower (intake) and upper (expulsion) valves may be identical,thereby further reducing the tools needed for manufacturing them. Forcomparison, the pumps commonly used in the art for bottles with aflexible pouch for cosmetic or pharmaceutical products generallycomprise between 15 and 20 components.

The pump is generally made of a plastic, such as polyethylene orpolypropylene of suitable density so as to give it the requiredmechanical properties.

The pouch may be made of a plastic selected for example from apolyethylene, a polypropylene, a polyamide, an ethylene/vinyl alcoholcopolymer (EVOH), a low-density polyethylene, etc. It may comprisemonolayer materials or multilayer complexes that include a metal layer,for example an aluminum layer forming a barrier that enhances thesealing, combined with one or more plastic layers.

The pouch may be manufactured from these materials by techniques such asblow molding as a single part, which has the advantage of reducing thenecessary manufacturing investment. It may also be produced by theinjection-blow molding or extrusion-blow molding of a parison in asuitable mold. The pouch may also be manufactured by welding a plasticor metal film, or a metal/plastic multilayer complex, onto a supportforming the neck of the pouch.

It may be advantageous to produce the pouch from a material matched tothe product that it contains. Thus, as an example, the pouch may be madeof low-density polyethylene when it has to contain a cream insensitiveto the effects of the external environment, whereas it may be made of apolyamide, providing better protection against the effects of oxygen andagainst the loss of water vapor by evaporation when it has to contain amore delicate product.

The advantages and features of the pump according to the presentinvention will become apparent in the non-limiting illustrative examplesdescribed in greater detail below, with reference to the appendeddrawings which show:

FIG. 1: a schematic sectional view of a pump mounted on the neck of arigid container, presented in the rest position with the pusher raised;

FIGS. 2 a and 2 b: a partial sectional view of a device for dispensingfluid, liquid or pasty products, comprising a pump as shown in FIG. 1mounted on a simple bottle, the pusher being in the high position (FIG.2 a) or in the low position (FIG. 2 b);

FIGS. 3 a and 3 b: a partial sectional view of an alternative version ofthe device of FIG. 2 in which the pusher, in the high position in FIG. 3a and in the low position in FIG. 3 b, is designed to expel a small doseof product;

FIGS. 4 a and 4 b: a partial sectional view of another alternativeversion of the device of FIG. 2 in which the travel of the pusher, inthe high position shown in FIG. 4 a and in the low position shown inFIG. 4 b, is limited by a sleeve;

FIG. 5: a sectional view of an alternative version of the device of FIG.1, comprising a dip tube and a vent at the bottom of the bottle;

FIG. 6: an enlarged sectional view of the dispensing nose of the pushercarrying a sealed closure cap; and

FIG. 7: an enlarged sectional view of an alternative embodiment of thepusher of FIG. 6.

The pump (1) shown in FIG. 1 is mounted on the body (2) of a rigidbottle via a cap (3). For this purpose, the cap (3) has a cylindricalhole (4) in which the body (5) of the pump (1) is housed so as to beable to slide therein.

The chamber (6) of the pump (1) is bounded by the lower valve (7), orintake valve, and the upper valve (8), or expulsion valve. The twovalves (7) and (8) are identical but mounted in opposition, as indicatedbelow, that is to say the intake valve closes when the expulsion valveopens, and vice versa, depending on the movements of the pump. As FIG. 1shows, the upper valve (8) is mounted on the end of the outlet nozzle ofthe pump.

The upper portion of the body of the pump has the form of a pusher (9)allowing the user to actuate the pump from the position shown in FIG. 1,by pressing down the pusher (9) against the metal helical spring (10)placed on the outside of the chamber, in such a way that it does notcome into contact with the product leaving the pouch. In this movement,the body of the pump slides in the cylindrical hole (4) of the cap (3)until the lower end (11) of the body (5) of the pump bears against theflange (12) integral with the tube (13) carrying the lower valve (7).

In this descending movement of the pusher (9), the lower valve (7)remains closed, while the upper valve (8) is open, allowing the productin the chamber (6) to leave.

When the user releases the pressure on the pusher (9), the body (5) ofthe pump (1) rises under the action of the spring (10) until thecircular retainer (14) comes into contact with the stop (15) formed onthe internal wall of the cylindrical hole (4) in the cap (3).

In this ascending movement of the pusher (9), the upper valve (8)remains closed, while the lower valve (7) is open, allowing the productin the pouch (16) to enter the chamber (6).

The pouch (16) is fixed via its neck (17) to the base of the tube (13)and rests on the shoulder (18) formed on the body (2) of the bottle. Theneck (17) may be fixed to the tube (13) by ultrasonic welding. The smallsize of the neck (17) of the pouch, i.e. less than one third of thecross section of the bottle, facilitates its manufacture by a simpleblow molding technique.

Since the pump is sealed and fixed to the neck (17) of the pouch (16),an air inlet circuit is provided so that the external air can enter thespace separating the pouch from the inner wall of the bottle so as tomaintain a sufficient pressure therein for the pouch to be able toretract at each expulsion of product. This air circuit is formed by thespace between the outer portion of the body (5) and the internal wall ofthe cylindrical hole (4), forming a channel that allows the air to passbetween the walls of the pump and the cylindrical hole. This channel isopen when the pusher is actuated, and it is closed when the pusher israised since, in this position, the annular rib (19) bears against theedge of the cylindrical hole (4) and closes off the channel.

The trials carried out with a device as shown in FIG. 1, comprising apump according to the invention, have demonstrated excellent uniformityof metering, and a reproducibility of around 90 to 95% in the case ofcreams, depending on their viscosity, and greater than 95% in the caseof liquids.

In addition, when used for the first time, the pump may be primed bypressing just three or four times on the pusher.

FIG. 2 shows the pump of FIG. 1 mounted in a sealed manner on a simplerigid bottle for fluids, preferably for liquids, in which the pump isextended in the bottle by a dip tube.

The pusher of the pump of FIG. 2 a is in the high position and thecircular retainer (14), located at the base of the pusher, is then incontact with the shoulder forming stop (15) on the internal face of thecylindrical hole that receives the pusher. When the user presses thepusher against the compression spring (10), the base (11) of the pushercomes against the flange (12) forming the bottom of the cylindrical hole(4) as shown in FIG. 2 b. The travel H1 of the pusher is indicated inFIG. 2 a and is equal to the distance separating the flange (12) fromthe base (11) of the pusher in the raised position.

The descending movement of the pusher causes the valve (8) to open andthe product lying in the metering chamber (6) to be expelled, while theintake valve (7) remains closed under the action of the overpressure inthe chamber.

When the user then releases the pusher, this rises under the action ofthe spring (10) and the partial vacuum thus created in the chamber (6)causes the intake valve (7) to open and the product coming from thebottle to enter via the dip tube (20), while the upper valve (8) remainsclosed. The metering chamber (6) thus fills up with a dose of product,which is ready to be expelled when the user next actuates the pusher.This dose of product remains protected from the external air thanks tothe sealing of the upper valve (8). In addition, because of the positionof the upper valve (8), no residual amount of product remains in contactwith the external atmosphere thereby limiting the risk of the outletorifice being blocked by accumulation of material.

In the embodiment shown in FIG. 3 a, the cylindrical base of the pusheris extended beyond the circular retainer (14), and the height H2separating the base (11) of the pusher from the bottom (12) of theflange is then shorter. The travel of the piston is limited to theheight H2 so that the pressure on the pusher causes only the expulsionof a partial dose from the chamber (6).

An equivalent embodiment is shown in FIG. 4 a, in which the pusher (9)is identical to that of FIG. 2 a but its travel is limited by acylindrical ring (21) placed in the bottom of the cylindrical hole, onthe base of the flange (12). The travel H3 of the pusher is then equalto the travel H1 of the device of FIG. 2 a, reduced by the height of thecylindrical ring (21).

FIG. 5 shows a rigid bottle (2) carrying the pump (1) of the invention,which includes the two valves (7) and (8) and the pusher (9). The bottle(2) is supplemented with a venting system (22).

The venting system comprises a plug (23) inserted into a hole providedin the bottom of the bottle (2) and carrying a filter (24) and a valve(25) of the usual type. The valve is designed so as to let the externalair enter the bottle only when a partial vacuum forms in the latter,that is to say when a dose of product is drawn up via the dip tube (20)of the bottle into the metering chamber (6).

Thus, air is introduced into the bottle (2) at each actuation of thepusher (9) of the pump (1) in order to compensate for the volume of thedose expelled, without contaminating the product contained in thebottle, thanks to the filter (24).

FIG. 6 shows a detail of the upper valve (8) carrying a shroud (26)mounted in a sealed manner on the nose of the pusher (9). Sealing isachieved by means of a rib (27) that cooperates with the base of thecylindrical shroud (26) made of an elastic material. Further sealing isachieved by the ribs (28) formed on the cylindrical base of the uppervalve (8). The shroud (26) thus completely envelopes the valve (8),ensuring that the device is closed off in a sealed manner.

As shown in FIG. 6, the product outlet nozzle comprises an annularorifice (29) surrounding a cylindrical element (30) lying opposite thehole (31) formed in the front face of the valve (8). In the closureposition, the front face of the valve (8) is applied against thecylindrical element (30) and masks the annular orifice (29). Because ofthe flexibility and elasticity of the material constituting the valve(8), an overpressure in the duct of the orifice (29) causes the edge ofthe valve around the central hole (31) to move away, letting the productleaving the metering chamber (6) to pass. The sealed shroud (26), bymasking the nose of the pusher (9), prevents any drop in externalpressure from causing the same phenomenon, and therefore ensures thatthe product contained in the bottle is safely stored.

In the alternative embodiment shown in FIG. 7, the cylindrical element(30) along the axis of the annular orifice (29) includes, on its frontface, a cylindrical protuberance (32) of the same axis as thecylindrical element (30). This protuberance forms with the front face ofthe cylindrical element a shoulder that cooperates with the edge of thecentral orifice of the valve (8), in such a way that the front surfaceof the cylindrical protuberance (32) is in the extension of the surfaceof the valve (8).

This embodiment allows the flow of fluid leaving the orifice (29) to beguided, even if the edges of the valve do not rise perfectlysymmetrically with respect to the axis of the annular orifice (29).

1. A manually actuated metering pump for a rigid bottle, of thedouble-valve type, comprising an intake lower valve and an expulsionupper valve at the inlet and at the outlet, respectively, of a meteringchamber that is mounted so as to slide on the lower valve, characterizedwherein the lower valve and the upper valve are identical.
 2. Themetering pump as claimed in claim 1, wherein the valves are ofcylindro-conical shape, comprising a dome pierced at its center, thewall of which, in the closure position, covers the annular outletorifice.
 3. The metering pump as claimed in claim 1, wherein the lowervalve is fixed to a hollow tube that communicates with the inside of thebottle.
 4. The metering pump as claimed in claim 1, wherein the uppervalve is mounted on the end of the outlet nozzle of the pump andconstitutes an outermost closure.
 5. The metering pump as claimed inclaim 1, wherein the valves are made of a material having a Shore Ahardness of between 40 and
 80. 6. The metering pump as claimed in claim1, wherein it includes means for limiting the travel of the pusher. 7.The metering pump as claimed in claim 1, wherein it is sealably mountedon the rigid body via a ring or a cap.
 8. The metering pump as claimedin claim 1, wherein it is mounted directly on the rigid bottle.
 9. Themetering pump as claimed in claim 1, wherein it is mounted on the neckof a flexible pouch placed in the rigid bottle.
 10. The metering pump asclaimed in claim 9, wherein it includes an air inlet circuit for air toenter the space separating the flexible pouch from the inner wall of therigid bottle.
 11. The metering pump as claimed in claim 10, wherein theair inlet circuit is located level with the pusher of the pump, andcomprises means for ensuring that it is closed off when the pusher israised, in the rest position.
 12. The metering pump as claimed in claim1, wherein it is sealably mounted on the neck of the rigid bottle, thebottom of which includes a vent.
 13. The metering pump as claimed inclaim 12, wherein the vent is provided with a valve and with a filter.14. A device for packaging and dispensing fluid, liquid or pastyproducts, wherein it comprises a metering pump as claimed in claim 1,associated with a rigid bottle.